超硬合金材料の硬さ試験は通常HRAスケールのみを使用します。 Cast iron materials often have the characteristics of uneven structure and coarse grains, so Brinell hardness test is generally used. Rockwell hardness tester can be used for hardness testing of some cast iron workpieces. Wherever there is not enough area for Brinell hardness test on the small section of fine-grained castings, HRB or HRC scales can often be used to test the hardness, but it is best to use HRE or HRK scales because HRE and HRK scales use 3.175mm diameter steel. ball, it can get better average readings than the 1.588mm diameter steel ball. For hard malleable iron materials, HRC is usually used. If the material is uneven, multiple data can be measured and the average value can be taken.
Cemented carbide (tungsten carbide) The hardness test of cemented carbide materials usually only uses the HRA scale.